An exemplary conventional electrical connector is shown in FIGS. 19A and 19B (see Japanese Utility Model Application Kokoku No. H3-5098). The electrical connector comprises a retainer that is inserted from the front surface of the housing, i.e., a so-called front insertion type retainer.
The electrical connector 101 shown in FIGS. 19A and 19B comprises an insulating housing 110, contacts 120 that are accommodated in this housing 110, and a retainer 130 that is inserted from the front surface of the housing 110 and that ensures that the contacts 120 are prevented from slipping out of the housing 110.
A plurality of contact accommodating cavities 111 for accommodating the contacts 120 are formed inside the housing 110. A housing lance 112 for accommodating the corresponding contact 120 is disposed inside each contact accommodating cavity 111. A space 113 that allows the flexing of the housing lance 112 is formed beneath each housing lance 112 (below in FIG. 19A).
Furthermore, the retainer 130 is constructed so that this retainer is inserted into the housing 110 from the front surface (left surface in FIG. 19A) of the housing 110, and comprises a plurality of regulating parts 131 that advance into the spaces 113 formed beneath the housing lances 112 and restrict the downward movement of the housing lances 112, thus ensuring that the contacts 120 do not slip out. A pair of locking parts 132 protrude from the side walls of the retainer 130 and are positioned to advance into locking holes 114 formed in both side walls of the housing 110 to prevent the retainer 130 from slipping out with respect to the housing 110. In this electrical connector 101, since the locking parts 132 enter the locking holes 114 formed in both side walls of the housing 110 when the retainer 130 is in the locking position, visual confirmation that the retainer 130 is in the locking position can be accomplished by visually inspecting the locking parts 132 from the outside of the housing 110.
An exemplary electrical connector 201 is shown in FIG. 20 (see Japanese Patent Application Kokai No. 2002-25705) which is constructed such that the locked state of the electrical connector and the mating connector can be confirmed by visual inspection. It should be noted that this is not an electrical connector of the type that is equipped with the front insertion type retainer.
The electrical connector 201 shown in FIG. 20 comprises a housing 210 that accommodates a plurality of female contacts (not shown in the figure), a supporting part (not shown) that protrudes upward from the housing 210, and a pair of arm parts 212 that respectively extend in the forward-rearward direction from the left and right side edges of the supporting part. Furthermore, locking projecting parts 213 are formed so that these parts 213 protrude from the front ends (upper ends in FIG. 20) of the respective arm parts 212, and operating parts 214 are formed on the rear ends of the respective arm parts 212. Furthermore, detection projecting parts 215 are formed so that these parts 215 protrude to the outside on the front ends of the operating parts 214 of the respective arm parts 212.
Meanwhile, the mating connector 301 that mates with the electrical connector 201 comprises a housing 310 to which a plurality of male contacts 311 are fastened, and a hood part 312 that surrounds the housing 310 and that extends forward (downward in FIG. 20). A pair of locking parts 313 to which the locking projecting parts 213 are secured at the time of mating with the electrical connector 201 are formed on the hood part 312. Furthermore, window holes 314 into which the detection projecting parts 215 advance when the locking projecting parts 213 are locked to the locking parts 313 are formed in the left and right side walls of the hood part 312.
In this electrical connector 201, since the detection projecting parts 215 advance into the window holes 314 formed in the hood part 312 of the mating connector 301 at the time of locking with the mating connector 301, the locked state of the electrical connector 201 with the mating connector 301 can be visually confirmed by visually inspecting the detection projecting parts 215 from the outside of the hood part 312.
However, the following problems have been encountered in these conventional electrical connectors.
Specifically, in the case of the electrical connector 101 shown in FIGS. 19A and 19B, the main body of the retainer 130 possesses rigidity against the locking parts 132 that are disposed on both side walls of this main body. Accordingly, when the retainer 130 is inserted from the front surface of the housing 110 and moved to the locking position, there is a danger that the locking parts 132 will be crushed by the side walls of the housing 110, or that the side walls of the housing 110 will be deformed. On the other hand, if the protruding height of the locking parts 132 is reduced in order to prevent the crushing of the locking parts 132 or deformation of the side walls of the housing 110, there is a danger that visual confirmation of the locking parts 132 when the retainer 130 is in the locking position will become difficult.
Furthermore, besides visual confirmation of the state of the retainer 130 in the locking position, there is also a demand for a method for measuring the height of the locking parts 132 from a specified reference by causing the inspection probe to contact the top surfaces of the locking parts 132 and thus detecting the state of the retainer in the locking position
Meanwhile, in the case of the electrical connector 201 shown in FIG. 20, each of the pair of arm parts 212 possesses flexibility, and has a structure that allows swinging inward and outward about the left and right side edges of the supporting part. Accordingly, each of the arm parts 212 can flex inward even in a state in which the detection protruding parts 215 have advanced into the window holes 314. In this electrical connector 201, when an attempt is made to measure the height of the detection protruding parts 215 from a specified reference by causing the inspection probe to contact the top surfaces of the detection protruding parts 215, each of the arm parts 212 flexes inward as a result of the pressing of the inspection probe, so that the detection protruding parts 215 are retracted to the inside, thus making measurement impossible. Accordingly, the locked state with the mating connector 301 cannot be accurately detected using an inspection probe.